To the enjoyment of millions of people, birds continue to coexist in nearly all environments with mankind. From the very beginnings of human civilization mankind has been fascinated by, and even revered, these musical, graceful, and colorful animals. Various clubs and societies devote enormous amounts of time observing the varieties of avian life and behavior. From the domestic canary to the wild bird of prey, people enjoy watching and being close to birds.
The metabolism of most birds requires them to consume large amounts of food in proportion to their sizes. Unless a bird is fully domesticated, this vital supply of food is not always readily available, particularly in the colder seasons. Wild birds will move from one area to the next looking for what small morsels they are able to find. Because of this behavior wild birds will, with seeming gratitude, quickly consume food given to them by man. Thus, it takes but a small handful of seed to enjoy the company of birds.
The desire for people to draw birds closer to their homes has led to various feeding devices. These devices range from very simple dispensers to rather complex forms aimed at being more decorative than functional. The majority of bird feeders operate in the same general manner. The devices have a storage chamber with an opening at the bottom. Attached to this bottom opening is a flat base mount with a surrounding wall on its outer edges. The base mount is attached so that gaps exist between the base and chamber. When the storage chamber is filled with seed, gravity forces the seeds out the bottom of the chamber and into the surrounding wall. The wall acts like a dam and stops the flow of seeds. As the seeds are eaten, more seeds continue to flow out of the bottom of the storage chamber until the feeder is empty. These types of feeders are not without drawbacks, however.
The straightforward design of a chamber and a base with surrounding wall does not take into account the manner in which birds eat. When confronted with a trough full of seeds birds will rapidly sweep their beaks from side to side while feeding. Whether the birds are searching for one particular seed, or sweeping aside empty husks resting on the surface, the end result is a shower of seeds falling to the ground. This is both wasteful and messy. In addition, adverse weather can completely empty such feeders in a short amount of time as gravity will continue to force the seeds into the surrounding wall as the wind either blows out the seeds, or tilts the feeder causing the seeds to spill out. If these events occur in cold whether, once the seeds are on the ground the sleet and snow can freeze the seeds making them inaccessible until the ice melts. In addition, wet weather can soak the seeds causing them to mold and disintegrate.
More advanced bird feeder designs provide a limited solution to these problems. One variety of structures consists of a polygon tube structure with a sealed bottom. The walls of the tube structure have side openings, with each opening having a damping structure for stopping the flow of seeds. The damping structure is typically in the shape of an inverted half-dome. These designs alleviate the problem associated with bird feeding habits, but continue to subject the feeder to the elements and thus can be wasteful and messy.
Another type of advanced bird feeder structure which may be found in the prior art are those which consist of "stacked" structures in which a number of funnel type structures are stacked on top of one another with feeding openings available to the sides are circumferentially surrounding each of the funnels. Some of these types of feeders may have as many as eight feeding holes available for use simultaneously. One consequent of the continuous gravity feed structures of this nature is that the number of available feed locations decreases as the supply of seed is depleted. That is, only those locations at the bottom of the gravity well will maintain feed as the supply vanishes from the upper locations.
The proliferation of types of bird feeders and methods for presenting seed to flying animals has resulted in a wide variety of potential structures. However, each variety has advantages and disadvantages in peculiar combinations, and none solve all of the problems associated with providing a secure and desirable feeder for avian creatures. Much room remains for improvement before the "ideal" bird feeder is perfected.